1.1 The Structure of DNA Flashcards
Describe the structure of inherited genetic material
- Found in DNA
- Contains all the genes that code for proteins
- DNA is in the form of a double stranded helix
- DNA is found in chromosomes most of the time
What is the genotype determined by?
The sequence of bases
What does DNA stand for?
Deoxyribose Nucleic Acid
What are the subunits of DNA called?
Nucleotides
What three components make up a nucleotide?
- Deoxyribose sugar
- Phosphate
- Base
What type of bonds hold the bases together?
Hydrogen Bonding
What two types of bonding hold DNA in its structure?
- Sugar Phosphate Bonds (strong backbone)
- Hydrogen Bonds (weak bonds)
The base Adenine pairs with what base?
Thymine
What are the base pairing rules?
Adenine - Thymine
Cytosine - Guanine
Why is DNA described as antiparallel?
- The strands run in opposite directions
- The strands are parallel
- 5’ to 3’ on one strand, 3’ to 5’ on the other
How is DNA organised in prokaryotes?
- Single circular chromosomes
- Plasmids
What are plasmids?
Rings of extra genetic material found in the cytoplasm
Where is DNA found in Eukaryotes?
Distinct Membrane bound Nucleus (In mitochondria and plasmids as well)
Describe the organelles in Prokaryotes?
- No membrane bound organelles
- No distinct nucleus
Describe the organisation of DNA in Eukaryotes
- Linear Chromosomes in Nucleus
- DNA tightly packaged around histones
- Circular chromosomes found in mitochondria and chloroplasts